RealmUI - Overview

RealmUI is the engine's declarative UI runtime. The host sends commands and ops (CmdUi*) and the core:

1. keeps document and theme state;
2. converts input (pointer/keyboard) to egui::Event;
3. renders UI meshes in the UI pass;
4. sends UI/system events back to the host.

Semantic Structure

• UiTheme:
  • reusable resource (visual tokens + fonts).
• UiDocument:
  • UI node tree bound to a realmId.
• UiNode:
  • declarative unit (kind + props) applied by CmdUiApplyOps.
• UiImage:
  • async image resource consumed by Image/ImageButton.

Integration with Targets/Layers

• UiImageSource::Target(targetId) enables sampling from an external target.
• UiNodeKind::WidgetRealmViewport renders target output inside a UI node.
• TargetKind::RealmPlane enables UI on a 3D plane with raycast/hit.

Reference

• Runtime: RUNTIME.md
• Widgets: WIDGETS.md
• Events: EVENTS.md
• Painter: PAINTER.md
• Limitations: LIMITATIONS.md
• Commands: docs/cmds/cmd-ui-*.md